At no time has He removed a king unilaterally. The king`s will is always the determining factor in his rise and fall.
Natural born talent, such as wisdom and intellect, can lie dormant unless the person with such talent wills to make use of it and to grow it.
In the case of Daniel, he was a gifted and talented man. But it was in his worship of the Lord, his attention to spiritual matters, that brought him into favor with God and man.